DE7616060U1 - PIPING, IN PARTICULAR EXHAUST PIPE, OF A MOTOR VEHICLE - Google Patents

Description

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Patent attorneys Olpl.-Ing. R. B EETZ senior Dipl.-Ing. K. LAMPRECHT Dr.-Ing. R. B E E T Z Jr.

Munich 22 ao.-tfcifuiJo IO Tel. (OBb) 33 73 01/33 73 44 / as SQ IO

Tnlegr. Allputanl Munich

578-25.616H

19-5 1976

Directed by Nationale des U3ine3 RENAULT, Boulogne Billancourt

(France)

Pipeline, in particular the exhaust pipe of a motor vehicle

The invention relates to a pipeline, one end of which is clamped and which experiences torsional stresses and the other end of which is articulated; in particular an exhaust pipe of a motor vehicle.

The object of the invention is to design a pipeline in such a way that the dangers of a break in the pipeline, which is subjected to bending and shear stress can be avoided.

578- (75/17236) -Lpsm

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The exhaust pipes in motor vehicles are subjected to a bending shear moment caused by vibration of the engine is conditional at start-up; this applies in particular to vehicles with a transverse engine. To such Known devices, particularly flexible ones, are in use to avoid the risk of pipe rupture or compliant components that allow for rotation within the pipeline without increased stress create. These resilient elements can either be sleeves with corrugated surfaces or pipe sections, made from a thin sheet of thin sheet metal wound into a helical line and has been crimped; this construction gives the pipe section a certain mobility.

These devices are generally suitable and correspond to the problem posed, but they are great expensive, the latter solution can also have sealing defects.

Other solutions are to limit the deflection of the motor directly by oscillations. Such a one Arrangement is not always applicable and its adjustment is delicate to the vibrations that arise the car chassis are transferred.

The present invention has the purpose of solving the problems of pipe breakage associated with a changing Torsional moment is claimed at their clamping point, which causes a bending of these tubes, and their end not swing freely because of the presence of obstacles, as in the case of the exhaust pipes mentioned above

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can be solved by relatively simple means.

The purpose of the invention is to reduce the degree of high stress near the clamping point by that the pipeline is enlarged by increasing its moment of inertia in this area, and also - by maintain a small deflection at the other end as this pipe inertia decreases lets how to move away from the clamping point by flattening while maintaining the same pipe thickness or local deformations are provided. With the same goal one can vary the thickness of the flats from the distance from the clamping point. Their position or location, their number and their thickness depend on them of course on the value of the maximum torque to which the pipeline is subjected.

In the case of an exhaust pipe, the local indentations or flats must be connected in a progressive manner be and must not contain angular parts in order to avoid disturbances in the flow of the exhaust gases May be a source of impermissible external noise.

For this purpose, the first local flattening is arranged as far as possible from the clamping point. You will expediently the muffler between this first flat and the pipe connection clamped on the engine arrange.

This inventive arrangement allows with a normal pipeline of constant wall thickness, which is not profiled, the use of the above-mentioned expensive

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Measurements of the stresses on such known devices have shown that only the front part of the Pipeline that is connected to the engine, is stressed with a very high alternating torsion, which is very quickly caused breaks in the area of the clamping point, while the rear part experiences a deformation that is practically zero.

With a pipeline designed according to the invention, which had, for example, three depressions or flats, a stress was found which in the The area of the clamping point was reduced by 60 ^, and had a constant low value over practically the entire length of the pipeline.

Generally speaking, the subject of the invention is a pipeline with a restrained end which undergoes torsional deformations while the other end is hinged; this pipeline is according to the invention characterized by an increase in their moment of inertia and their rigidity in the area of their clamped End and through a series of localized reductions in their moment of inertia in their mean Part. In this central part, the torsional stresses are absorbed and distributed in a limited way be taken up by the pipeline in the area of its clamping point.

The localized reductions in their moment of inertia are advantageously provided by flats

of the circular cross-section of the pipeline into an elliptical Cross-section generated, which siah steadily at the KrelsquersohnlUt connect. This arrangement is particular to any automobile exhaust pipe with a forward Engine suitable, which is connected to the exhaust manifold of the engine concerned and a flexible one Has attachment point that is hinged to the chassis at the rear of the vehicle.

The stiffening of the moment of inertia in the clamping area on the exhaust manifold is advantageously achieved by creates an intermediate clamping sleeve that is rigidly connected to the engine via arch supports or fastenings.

In this solution according to the invention you can use the silencer or a reaction vessel to eliminate the Pollution of the exhaust gases as a stiffening element in the pipeline immediately behind the reinforced Install clamping zone.

In this way the problems of pipe rupture are solved with an inexpensive device with such exhaust lines.

An embodiment of a pipeline according to the invention will now be made with reference to the drawing are described in which represent:

Fig. 1 shows an exhaust pipe as it is in a vehicle is installed with a transverse engine in the front j

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Fig. 2 shows an enlarged detail of the pipeline at the level of a local flat, which reduces the moment of inertia of the pipeline;

Fig. 2 shows the cross section of such a flattening.

In the wing. 1 is shown in part the outline of an engine 1 installed at the front end of a motor vehicle which itself is not shown, is installed transversely. A clamping piece 2 Is rigidly connected to the exhaust manifold j5, possibly reinforced by support arch 4 to connect with the engine 1 to form rigid block.

This clamping piece takes the exhaust line 5, which includes a muffler 6 near the engine and an attachment point 7 on the one not shown Has carriage chassis at the rear, opposite end. This pipeline has in its central or middle part a series of local flats 8, which the moment of inertia of the pipeline 5 in the plane of this Reduce flattenings and so in the example described the formation of an antinode in the area of the flattened areas 8 favor. These flats speak to the torsional vibrations of the entire stiffer sections 1,2,3 » ^! and 6, especially when starting the engine 1, without im essential to influence the attachment point 7, which a vibrating metal bracket 9 a certain resilience there, and without. Concentrations of disruptive stresses in the area of the connection point or the connection piece 2 to evoke.

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Compared to the known solutions that strive to by expensive means, the compliance in the dom area is close

the clamping position to be used when fastening the runner to the engine;

greater, where the Bruchgo danger occurs, increases the I

. de solution the stiffness In this zone down to the under-;

pressing the alternating torsional stresses In the;

total stiffened area subject to engine movements j

follows and the torsional deformations are applied to the local j

Flattened zones 8 transferred and distributed longitudinally where they |

no longer give rise to the risk of breakage. !

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In the example of FIG. 1, the desired 1st stiff- \ Fung also achieved that f the muffler 6 arranges here. This solution is also interesting because you are here! can arrange the reactors against the pollution of the exhaust gases at the outlet of the exhaust manifold in order to receive the gases with the highest possible temperature there.

FIGS. 2 and 3 show, on an enlarged scale, an example of the machining of the pipeline 5> in order to preserve the local flats that make the pipeline "softer". By putting the pipe between suitable Pressing shaping elements, one causes an impression that progressively proceeds from the circular cross-section to to obtain the ellipsoidal cross section 10 of FIG. This form of progressive connection diminishes that Pressure loss and the dangers of generating noise when exhaust gases flow in the pipeline to the greatest extent; at the same time, a good distribution of the bending stresses in the material is achieved.

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Claims (3)

ill IUI protection claims 1. Pipeline, one end of which is clamped and is subjected to torsional loads and the other end is hinged, marked by increasing their moment of inertia and their rigidity in the region of their restrained end and by a series of localized reductions their moment of inertia in their middle part. 2. Pipeline according to claim 1, characterized in that that the localized reductions in their moment of inertia due to flats (8) of the circular cross-section of the pipeline (5) are produced in an ellipsoidal cross-section, this cross-section increasing steadily adapts to the circular cross-section or merges into it. 3. Exhaust pipe of a motor vehicle with the front Engine that connects to the exhaust manifold of this engine and has a resilient attachment point, which is articulated on the rear wall of the vehicle, according to claims 1 and 2, characterized in that the reinforcement of the moment of inertia in the clamping zone on the exhaust manifold (2) is achieved by an intermediate clamping sleeve (2), which is is rigidly fixed to the engine by fastening juni £ s-BogenslUt7.en ( ^{; t).} i \. Exhaust pipe according to claim '}, characterized in that the silencer (6) forms a stiffening element and is built into the pipe (5) immediately behind the reinforced clamping zone (2). 7616060 11/04/76